Question

if a =9+4√5,find a + 1/a
​

Answer 1

Answer:

18 is your answer

Refer to the attachment

hope it helped u :)

Answer 2

Step-by-step explanation:

$a = 9 + 4 \sqrt{5}$

$a + \frac{1}{a}$

$9 + 4 \sqrt{5} + \frac{1}{9 + 4 \sqrt{5} }$

$\frac{1 \times 9 - 4 \sqrt{5} }{9 + 4 \sqrt{5} \times 9 - 4 \sqrt{5} }$

$\frac{9 - 4 \sqrt{5} }{81 - 80}$

$9 + 4 \sqrt{5} - (9 -4 \sqrt{5} )$

$9 + 4 \sqrt{5} - 9 + 4 \sqrt{5}$

$8 \sqrt{5}$

may be it helps you...

plz follow me ......